In usual ground excavation methods, excavation stabilizing liquid is used, which comprises main components such as inorganic clay and, in some cases, water soluble high polymer, a dispersant such as sodium polyacrylate or sodium hexametaphosphate, and additives such as various types of antiseptics.
In the usual technique, however, the prevention of the deterioration of excavation stabilizing liquid by seawater or cement mixing in or of the putrefaction of the stabilizing liquid composition has been insufficient, leading to the large labor and cost for the ground excavation.
The object of the invention is, in the ground excavation, to provide a composition suited for addition to excavation stabilizing liquid which is able to prevent effectively the deterioration of stabilizing liquid by seawater or cement mixing in and to prevent the putrefaction of the liquid by bacteria, to provide an excavation stabilizing liquid composition, and to provide a method for excavation using these compositions.